The present invention relates to an improved bush-cutter for the mowing of grass and the like according to the first part of the main claim.
The well-known bush-cutter tools essentially include a rod or a stiff arm, working as a handle, that supports at one end a cutting head rotating around an axis and having cutting means with a cutting element, for example a blade or a flexible rope made of nylon or the like, and on the other end engine means, for example a combustion engine, which make the cutting head rotate through gearing mean.
In order to mow the grass, the operator grips the tool arm and moves forward, placing the cutting head near the ground and with its axis of rotation substantially orthogonal in respect of the same, while through manual control means he adjusts the speed of rotation of the engine and consequently the speed of rotation of the cutting head. The cutting means, rotating together with the cutting head, mow the grass very close to the ground.
However, often during the mowing the cutting means accidentally touch the base of trees and shrubs trunks, causing the unwelcome barking, or other obstacles with the damages that this implies. This is partially due to the particular structure of the cutting means, which do not allow the operator to perceive the right distance to be kept in order to avoid the barking or even the cutting of the trunks, if they are small stock shrubs. EP-A-0.603.982 discloses a bush-cutter which comprises spacing means, including a spacer which swings around an axis parallel to the axis around which the cutting head rotates.
According to U.S. Pat. No. 5,048,187 both axis of the spacer and the cutting head could be coincident.
In this bush-cutter the spacer is normally maintained in a working position in which, during the mowing of the grass, selectively contacts any possible obstacle at a radial distance from the cutting head, that is longer than the radial extension of the cutting element of said cutting means in respect of the head, avoiding the contact of said cutting element with the obstacle.
However, when the bush-cutter is handled according to the normal forward direction of its cutting head, the spacer maintained in its working position could affect negatively the mowing of the grass.
It is therefore the principal object of the present invention to provide an improved bush-cutter for the manual mowing of grass and the like, that allows to avoid the barking of trees and shrubs trunks and, anyhow, the contact of its cutting means with objects that have not to be damaged during the mowing, without negatively affecting the moving of the grass when the bush-cutter is handled according to the normal forward direction of its cutting head.
Another object of this invention is to provide an improved bush-cutter, the construction of which can be simplified and which is safe and reliable and easy and comfortable to be used.
With these objects in view, the present invention provides a bush-cutter for the mowing of grass and the like, whose essential characteristic is the subject of the characterizing part of the main claim, which should be regarded as incorporated here in its entirety.
Further advantageous features are described in the dependent claims.